Cutting chains for mining machinery



Feb. 11, 1958 c. B. KREKELER CUTTING CHAINS FOR MINING MACHINERY Fi led Oct. 15, 1956 1N VEN TOR. (Z 41/05 .5. KIEIKEZ if, BY

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2,822,699 CUTTWG CHAINS FOR G MACHINERY Claude B. Krekeler, Mack, (Bhio, assignor to The Cincinnati Mine Machinery (30., Cincinnati, Ohio, a corporation of ()hio Application Oetober 15, 1956, Serial No. 615,811

11 Claims. (Cl. 74-250) The invention relates to cutting chains and has for its principal object the provision of means tending to prevent the packing of cuttings and impurities in the interstices of the chains whereby their operation is impaired.

Usually cutting chains are made'up of double link members which carry sockets for cutter bits and are characterized by spaced chain parts or checks, and single link members, hereinafter called connectors. These parts are held together by suitable pintles. In some constructions the link elements have single checks on one end and double checks on the other. The chain passes about a cutter bar, and is driven by a sprocket in the body of the mining machine. The teeth of the sprocket engage in cavities in the link members beyond the end or ends of the single cheeks. For clarity, those parts of the link members which are interengaged at their end portions and pivoted together by means of the said pintles are called cheeks, whether single or double. Thus, in all types of mining machinery cutting chains, the end portion of a single. check of one member or element will be engaged between end portions of spaced or double checks of the next succeeding part of the chain, and pivoted thereto by a pintle.

In the normal use of a coal-cutting chain, trouble is-frequently encountered by reason of the entrapment of cuttings and impurities in the said cavities. In the exemplary disclosure, the cavity is that space bounded laterally by the checks of the link member, fore and aft by the ends of the connectors, and above by the socket member of the double link, i. e. that space into which the teeth of the drivingsprocket enter. After many successive passes of the chain elements over the sprocket teeth, cuttings tend to pack in the cavities so that the sprocket teeth can no longer enter them fully or easily. This causes the chain to ride up over the top of the sprocket teeth, producing excessive tensional stresses on the chain. There is also some tendency for cuttings and foreign materials to pack between the ends of checks of the double link members, which produces a power loss when thechain runs in the guides of thecutter bar.

Specifically, an object of the invention is the provision of means which, operating in the aforesaidcavities when the chain is flexed, displace the cuttings and impurities, minimizing packing, and causing the cutting to drain from the cavities.

This and other objects of the invention, which will be set forth hereinafter or will be apparent to one skilled in the art upon reading these specifications, are accomplished by that construction and arrangement of parts, of which an exemplary embodiment will now be described. Reference isrnade to the accompanying drawings, wherein:

Figure l is a partial plan view, semi-diagrammatic in nature, of a cutter bar and cutter chain, showing the driving sprocket and a portion of the mining machine.

Figure 2 is a plan view with parts in section showing the engagement of the chain with the sprocket.

Figure 3 is a perspective view of a chain connector element embodying the invention.

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Figure 4 is a partial elevational view of a cutter chain showing the application of lugs to the "checks of the double link elements.

Figure 5 is a similar view' showing another lug arrangement.

Briefly, in the practice. of the principal phase of the invention, vane-like members are provided on the ends of the chain connector elements, so positioned as to lie within: the cavities aforesaid; When the chain is straight, these: vanes lie across the cavityand above that part of it which will be occupied by a sprocket tooth.- When the chain flexes, as in passing-about the end of the cutter bar or about the sprocket, the vanes have a'substantial range of movement within the cavity. Thus they displace andv break up accumulations-within the cavity, arid reduce the packing pressure on the flats of the sprocket teeth, enabling; the sprocket teeth to displace the foreign materials.

In the drawings a portion of a mining machine is indicated at 1. A- cutter'bar is diagrammatically indicated. at 2. It is ordinarily pivoted to the mining machine in a suitable way, and it provides a channel in which a cutter chain 3 rides. The cutter chain is driven by a powered sprocket 4 in or on the body of the mining machine. The chain is made up of a series of double link elements having spaced cheeks indicated at 5 and 6 (Figure 2). These checks are held in spaced relationship by and are integral with a block-like socket element 7. The socket element is perforated as at 8 to receive the shank 9 of a cutter bit or cutter bit holder which is usually but not necessarily held in the perforation S'by a set screw 10. For the purpose of an exemplary showing, thecutter bits herein have been illustrated as of the one-piece variety having the shank 9 and ahead 11 bearing a hard alloy cuttingelement 12. The nature of the cutting bit forms no limitation on this invention; and the invention is equally applicable to chains in which the socket elements engage cutter bit holders which, in turn, carry replaceable, double-ended bits, all as is well known in the art. a

The double link chain elementsalternate with single link elements 13, the ends of which lie between the checks of the double link elements, the parts being hinged together by suitable pintles 14 which may be held in place by rivets 15 or otherwise as is known in the art. An exemplary single link element is illustrated in Figure 3. It is perforated as at 16 and 17 for the reception of the pintles aforesaid.

-During the cutting operation quantities of fine cuttings tend to enter the cavities ofthese chains. Aswill be evident from Figure 2, there is a substantial space 181ocated between the cheeksS and 6 of the double link elements and between the ends of the single link elements, these spaces or cavities being partially closed at the outer side of the chain by the socket member 7 and the associated bit or bit holdershank. The teeth 4a of the driving sprocket 4 must'enter these cavities as the chain is driven by the sprocket. Many types of cuttings are of such nature that they tend strongly to pack under pressure and, as will be evident, the teeth 4a of the sprocket exert packing pressure when they enter the cavities if the cavities contain substantial quantities of cuttings. This is why the accumulation and packingof cuttings within thecavities tends to prevent the full entry of the sprocket teeth into the cavities, and interferes with theproper driving of the chain while subjecting the chain -to undue longitudinal stresses.- It has been found that this tendency can be greatly alleviated and in most instances obviated entirelyby providing vanes 19 and 20 on the ends of the single link elements of the chain. These vanes extend generally radially with respect to the pintle, receiving perforations 16'and 17 and are so placed'that-a vane on one connector or single link element extends vwithin the cavity toward a vane of the next"succeedingconnectoi l 3 When the chain is straight, the placement of these vanes is such that they extend inwardly partially across the cavity without obstructing that part 18a of the cavity which is to be entered by a sprocket tooth 4a, as will be clear from Figure 2. When the chain is flexed, as in its passage around the end of the cutter bar, or around the sprocket 4, these vanes move away from each other through a considerable range of motion, as will be evident at 19a and 20a in Figure 2. In so moving, they break up and displace accumulations of cuttings within the cavity 18, tending to remove these cuttings from the cavity through the spaces between the socket member 7 and the ends of the single link elements. The entry of a sprocket tooth into the cavity tends still further to displace cuttings therein since pressure is relieved and the cuttings are prevented from packing by the vanes.

The width of the vanes, i. e. the distance they extend into the cavity 18, will be proportioned to the size of the cavity and the placement of or clearance provided by the socket member 7. In some types of construction, it will be possible to have the vanes span substantially the entire width of the cavity. A plurality of vanes may be employed on the ends of the single link elements providing they are so placed as not to obstruct the sprocket tooth socket portion 18a of the cavity.

As indicated above, cuttings and foreign materials tend also to pack in the spaces or cavities at the sides of the chain, which cavities lie between the ends of coplanar cheeks of successive double link elements, and are bounded on the inside by central portions of single link elements. These cavities are indicated in Figures 4 andS at 21. While the sprocket teeth do not enter these cavities, the packing of foreign materials therein tends to increase frictional drag with a resulting power loss, especially since the chain travels for considerable distances in grooves or channels in the cutter bar. By an adaptation of the principles set forth above, it is possible to alleviate the packing in these cavities also by the formation of vanes 22 and 23 on end portions of the cheeks of thedouble link members. As shown in Figure 4 these vanes may be located substantially in the plane of the axis of'the pintles in a given cheek; they may approach each other across the cavity and as the chain turns about the sprocket or at the outer end of the cutter bar, they will tend to break up any agglomeraion of packed materials within the cavity. Since no sprocket teeth enter the cavity, the cheek ends may be provided each with a number of vanes, or the vanes may be given a placement other than that shown in Figure 4. Thus one or more vanes may be located on the end of one cheek in a position below the plane of the center lines of the pintles of that cheek, while the vane or vanes on the next succeeding cheek end may be located thereabove and the like. A modified structure of this character is shown in Figure where a vane 24 is located at or near the lower edge of one end of the cheek 6a While vane 25 is located near or at the upper edge of the cheek 6b. In the illustrated instance the vane 25 is prolonged so as substantially to span the cavity 21. In this configuration the vane 25 serves a dual purpose. It tends not only to break up or relieve the pressure on any materials which may have become packed in at cavity ll, but also by closing or nearly closing the top of the cavity it tends to impede or control the entry of foreign materials into the cavity.

Both the double link elements and the single link elements or connectors are preferably formed as forgings; and the vanes may readily be formed integral with the connectors or checks during the forging operation.

Modifications may be made in theinvention Without departing from the spirit of it. The invention having been described in an exemplary embodiment, what is claimed as new and desired to be secured by Letters Patent is:

l. A mining machine chain made up of alternate double link members and single link members, in which the double link members each have two cheeks integral with and held in spaced relationship by a socket member, and in which the ends of said single link members are engaged between the cheeks of the adjoining double link members and pivoted thereto by pintles, there being cavities between said cheeks and between the ends of said single link elements, which cavities are entered by the teeth of a driving sprocket for said chain, means for minimizing the packing of cuttings in said cavities, said means comprising projections on the ends of said single link members adapted to move within said cavities when said chain is flexed. p

2. The structure claimed in claim 1 wherein additional cavities exist between the ends of cheeks of successive double link members, and wherein the ends of said checks are provided with vanes extending into said last mentioned cavities. v

3. The structure claimed in claim 1 wherein said projections are in the form of vanes integral with said single link members and extending transversely of the ends thereof.

4. The structure claimed in claim 1 wherein said projections extend toward each other in a direction across each said cavity when said chain is straight, and are so located as to lie beyond that portion of the cavity which will be occupied by a tooth of the said sprocket.

5. The structure claimed in claim 2 in which said vanes extend toward each other ina direction across each said cavity when the said chain is straight and have movement away from each other and outward when said chain is flexed, there being sufficient clearance between the said socket element and the ends of the said single link elements to permit said vanes to displace cuttings through said clearance.

6. The structure claimed in claim 4 wherein additional cavities exist between the ends of the checks of successive double link members and wherein the ends of said checks are provided with vanes projecting into the said last mentioned cavities.

7. The structure claimed in claim 4 wherein additional cavities exist between the ends of the cheeks of successive double link members and wherein the ends of said cheeks are provided with vanes projecting into the said last mentioned cavities, and in which one of the said vanes projects substantially entirely across an upper portion of the said cavity so as to inhibit the entrance of cuttings therein.

8. A mining machine chain characterized by double link elements alternating with single link elements, said double link elements having cheeks integral with and spaced by a socket member, the ends of said single link elements being located between said cheeks and pivoted thereto by means of pintles, the ends of said single link elements being spaced to form a cavity for engagement with the teeth ofa driving sprocket which engage the ends of the single link elements, and means on the ends of said single link elements and projecting into said cavities for breaking up accumulations of material which would tend to pack in said cavities, said projections being located on portions of the ends of said single link elements not engaged by said sprocket teeth.

9. A mining machine chain characterized by link elements pivoted'together in succession, said link elements having cheeks, the checks of spaced elements in said chain approaching each other endwise but spaced so as to leave cavities in said chain therebetween, and means forbreaking up the packing of foreign materials in the said cavities, said means comprising vanes on the ends of said cheeks extending into the said cavities and moving therein when said chain is. flexed.

10. A mining machine chain characterized by link ele ments having portions interengaged and pivoted together in succession, said link elements having checks, the interengagement between successive ones of said link elements being such that a single cheek of one element has an end portion located between end portions of spaced cheekS of an adjacent element and pivoted thereto, there being a cavity in said adjacent element beyond the end portion of the single check, the end portion of said single cheek bearing a vane extending into said cavity and moving therein as the chain is flexed.

11. The structure claimed in claim 10 in which additional cavities exist between the end portions of said spaced cheeks and an adjacent element, and in which the References Cited in the file of this patent UNITED STATES PATENTS Simmons July 13, 1943 Vanderzee Dec. 19, 1944 Simmons Jan. 8, 1952 Hinkley Dec. 29, 1953 

